The A & AL series of Rockford Linear Bearing Blocks have a standard profile and a tapped/through hole with a flange. These blocks are available in either a standard length block (A) or a long-length block (AL). Each bearing block has 4 circular arc raceways; each raceway has a 45º contact angle which allows for equal loading in all directions. The raceways and Double Face Configuration (also known as "X" configuration) offers high-rigidity and tolerates misalignments of the rail. End seals are standard features on each block; most sizes also have a long-life lubrication reservoir, a metal seal retention frame and side seals. Additional accessories such as end seals and scrapers are also available for the A & AL blocks.